This compound can be used in conjunction with a variety of biological samples and is sometimes used as an alternative to lead acetate after uranyl acetate. This approach can be used for both electron as well as light microscopy and the actual working solution can be prepared easily.
Furthermore, bismuth tends to interact with reduced osmium (e.g. the form of osmium after it has been reduced and has oxidized some element in the tissue), and therefore can act as a contrast enhancing stain for phosphotungstic acid. For example, it brings out additional contrast in samples with DNA, ferritin, and lysosomes.
